Alarm sounded, nations urged to act at UN climate talks

With the direst warnings yet of impending environmental disaster still ringing in their ears, representatives from nearly 200 nations gather Sunday in Poland to firm up their plan to prevent catastrophic climate change. The UN climate summit comes at a crucial juncture in mankind's response to planetary warming. The smaller, poorer nations that will bare its devastating brunt are pushing for richer states to make good on the promises they made in the 2015 Paris agreement.